/* 
 * [New BSD License (BSD 3-Clause License)]
 * Copyright (c) 2012, Max Bechtold
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *     - Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     - Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     - Neither the name of the Rel2Xml Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package maxbe.rel2xml.generator.dml;

import java.util.ArrayList;
import java.util.List;

import maxbe.rel2xml.generator.docs.DataType;

/**
 * Represents an assignment of the form "set col1 = val1". val1 can be an
 * expression with arithmetic operators and can contain column references. These
 * will be replaced when translating to XQuery, but note that this will leave
 * dangling placeholders when using column references in updates of columns that
 * are not specified as <i>not null</i> or that are implicit.</br> Also used in
 * column initializations of Insert expressions.
 * 
 * @author Max Bechtold
 * 
 */
public class Assignment {

	/** The column that is assigned */
	private final ResultColumn column;

	/** The value that is assigned, with placeholders for column references */
	private String value;

	/** Ordered list of column references */
	private List<ResultColumn> colRefs;

	public Assignment(ResultColumn column, String value,
			List<ResultColumn> colRefs) {
		this.column = column;
		this.value = value;
		this.colRefs = colRefs;
	}

	public ResultColumn getColumn() {
		return column;
	}

	public String getValue(String context) {
		List<String> refs = new ArrayList<String>(colRefs.size());

		for (ResultColumn colRef : colRefs) {
			String format = (colRef.getColumn().getDataType() == DataType.INTEGER ? "xs:integer(fn:data(%s/%s))"
					: "fn:data(%s/%s)");
			refs.add(String.format(format, context, colRef.getXmlName()));
		}

		return String.format(value, refs.toArray());
	}

	public String getValue() {
		return value;
	}

	public List<ResultColumn> getColRefs() {
		return colRefs;
	}

	public void setValue(String value) {
		this.value = value;
	}

	@Override
	public String toString() {
		return String.format("%s = %s", column.getName(), value);
	}
}
